When comparing different VR devices, it's important to consider their features and specifications. Resolution, field of view, refresh rate and tracking are the most important ones. Resolution determines the sharpness and clarity of images, with higher resolution meaning better quality, but also more power consumption and cost. The average resolution is around 1080 x 1200 pixels per eye, but some devices can go up to 2160 x 2160 pixels per eye. Field of view is the angle of vision that the VR device covers, with wider field of view meaning more coverage, but also more distortion and blurriness at the edges. The average field of view is around 100 degrees, but some devices can go up to 130 degrees. Refresh rate is the number of times the screen refreshes per second, with higher refresh rate meaning less lag and motion sickness, but also more power consumption and cost. The average refresh rate for VR devices is around 90 Hz, but some devices can go up to 144 Hz. Tracking is the system that tracks head and body movements, with two types: inside-out and outside-in. Inside-out tracking uses cameras on the device to map surroundings while outside-in tracking uses external cameras or base stations for better precision and stability.